.middle {
    margin: 50px 0;
    display: flex;
    justify-content: center;

}

.middle > div {
    width: 1000px;
    border: 1px solid red;
}

.middle > div > div:nth-child(1) {
    border-bottom: 1px solid red;
}

.middle > div > div:nth-child(2) {
    padding: 10px;
    overflow: hidden;
}

/*--------------------内容------------------*/
.content > div {
    display: flex;
    justify-content: center;
    margin: 30px 0;
}

.content > div:nth-child(1) > div:nth-child(1) {
    width: 800px;
}

.content > div:nth-child(1) > div:nth-child(1) > div:nth-child(1) {
    display: flex;
    justify-content: center;
}

.content > div:nth-child(1) > div:nth-child(1) > div:nth-child(1) > div {
    display: flex;
}

.content > div:nth-child(1) > div:nth-child(1) > div:nth-child(1) > div > div:nth-child(1) {
    color: orange;
}

.content > div:nth-child(1) > div:nth-child(1) > div:nth-child(1) > div > div:nth-child(2) {
    color: gray;
}

.content > div:nth-child(1) > div:nth-child(1) > div {
    text-align: center;
}

/*----------------------提交---------------------*/


.content > div:nth-child(2) > div {
    width: 600px;

}

/*--------------------留言--------------------*/
.online > div:nth-child(1) > div > div {
    line-height: 30px;
    height: 30px;
}

.online > div:nth-child(1) > div > div:nth-child(2) {
    background-color: rgb(238, 238, 238);
    border: 1px dashed gray;
    padding: 0 10px;
}

.online > div:nth-child(1) > div:nth-child(3) > div:nth-child(2) {
    height: 100px;
}

.online > div:last-child {
    display: flex;
    justify-content: center;
}

.online > div:last-child > div {
    color: white;
    background-color: orange;
    padding: 5px 40px;
    margin: 20px;
    cursor: pointer;
}